Northvolt transformed in a matter of months from Europe's best shot at a homegrown electric-vehicle battery champion to a struggling company.

Northvolt, the Swedish maker of battery cells for electric vehicles, said on Thursday it has filed for Chapter 11 bankruptcy protection in the U.S., dealing a blow to Europe's hopes that its most developed battery player would reduce Western car makers' reliance on Chinese rivals.

Swedish battery maker Northvolt filed for Chapter 11 bankruptcy protection in the U.S., delivering a blow to Europe’s electrification ambitions.